1. Field of the Invention
This invention relates to a test tube holder for use in carriage of a test tube containing a specimen such as blood.
2. Description of the Related Art
A test tube containing a specimen such as blood is formed of transparent glass or plastic. A cap formed of rubber or synthetic resin is put on an upper opening portion of the test tube. The test tube is carried to each of processing sections, while being vertically held by a test tube holder and guided along a carrier passage, in order that the specimen contained in the test tube be served or poured into another test tube.
Therefore, the test tube holder is formed to stably and vertically hold each of kinds of test tubes having different lengths and diameters, when each test tube is carried. The test tube holder has a base body constituting a holder body. The base body is formed rotation-symmetrically with respect to an axis extending along a vertical direction. Furthermore, an engaging portion provided at an outer peripheral surface of a proximal end portion of the base body. The engaging portion is engaged with a guide rail of a conveying system. A cylindrical hollow portion for accommodating a test tube is provided in a center portion of the base body to extend from an upper end of the base body to a predetermined depth toward a proximal end of the base body. Furthermore, Jpn. Pat. Appln. KOKAI Publication No. 2003-211006 discloses a test tube holder providing with an adapter which enables a test tube having a diameter falling within a given diameter range to be inserted into the test tube holder, and which is provided in a cylindrical hollow portion of a holder body.
In particular, it should be noted that the test tube holder disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2003-211006 has a plurality of leaf springs provided in the cylindrical hollow portion of the holder body. The leaf springs have contact portions which contact the outer peripheral surface of a test tube to be held. The test tube holder includes one O-ring which bundles the leaf springs in such a way as to surround them, in order that the contact portions press the outer peripheral surface of the test tube at a given pressure.
In the above test holder, the elasticity of the leaf springs is compensated for by the O-ring, and the structures of the leaf springs and peripheral members thereof are complicated. Thus, the parts of the test holder cannot be easily assembled, as a result of which the manufacturing cost is increased, and the maintenance is troublesome when the O-ring is damaged or broken.